NASA’s newest six-wheeled robot on Mars, the Perseverance rover, is beginning its epic journey across the Jezero crater floor seeking signs of ancient life. What makes that exciting for this mission is that Perseverance is equipped with the most powerful navigation software that’s ever been sent to another planet.
The distance between Mars and Earth doesn’t make it practical to drive the rover in real-time with a human driver. In fact, this has never been possible. All of the prior rovers also had to rely on autonomous driving to move across the planet.
However, the team at JPL has learned from each subsequent mission to Mars and as a result, the Perseverance rover is the most capable, auto navigating rover to ever be deployed. Armed with these new capabilities, the team expect Perseverance to take on more of the planning and obstacle avoidance onboard the rover. The result will be longer drives and more mileage driven throughout the mission lifetime.
The new powerful auto-navigation system is called AutoNav. It includes and enhanced system that makes 3D maps of the terrain ahead, identifies hazards, and plans a route around any obstacles without additional direction from controllers back on Earth.
“We have a capability called ‘thinking while driving,’” said Vandi Verma, a senior engineer, rover planner, and driver at NASA’s Jet Propulsion Laboratory in Southern California. “The rover is thinking about the autonomous drive while its wheels are turning.”
That capability, combined with other improvements, might enable Perseverance to hit a top speed of 393 feet (120 meters) per hour; its predecessor, Curiosity, equipped with an earlier version of AutoNav, covers about 66 feet (20 meters) per hour as it climbs Mount Sharp to the southeast.
“We sped up AutoNav by four or five times,” said Michael McHenry, the mobility domain lead and part of JPL’s team of rover planners. “We’re driving a lot farther in a lot less time than Curiosity demonstrated.”
As Perseverance begins its first science campaign on the floor of Jezero Crater, AutoNav will be a key feature in helping get the job done.
This crater once was a lake, when, billions of years ago, Mars was wetter than today, and Perseverance’s destination is a dried-out river delta at the crater’s edge. If life ever took hold on early Mars, signs of it might be found there. The rover will gather samples over some 9 miles (15 kilometers), then prep the samples for collection by a future mission that would take them back to Earth for analysis.
“We’re going to be able to get to places the scientists want to go much more quickly,” said Jennifer Trosper, who has worked on every one of NASA’s Martian rovers and is the Mars 2020 Perseverance rover project manager. “Now we are able to drive through these more complex terrains instead of going around them: It’s not something we’ve been able to do before.”
Perseverance can’t get by on AutoNav alone. The rover management team back on Earth at JPL remains critical in planning and driving Perseverance’s route. An entire team of specialists develops a navigation route along with planning the rover’s activity, whether it’s examining a geologically interesting feature on the way to its destination or, soon, taking samples.
Perseverance’s wheels were modified as well to help with just how swiftly those plans are executed: Along with being slightly greater in diameter and narrower than Curiosity’s wheels, they each feature 48 treads that look like slightly wavy lines, as opposed to Curiosity’s 24 chevron-pattern treads. The goals were to help with traction as well as durability.
“Curiosity couldn’t AutoNav because of the wheel-wear issue,” Trosper said. “Early in the mission, we experienced small, sharp, pointy rocks starting to put holes in the wheels, and our AutoNav didn’t avoid those.”
Higher clearance for Perseverance’s belly also enables the rover to roll safely over rougher ground – including good-size rocks. And Perseverance’s beefed-up auto-navigation capabilities include ENav, or enhanced navigation, an algorithm-and-software combination that allows more precise hazard detection.
Unlike its predecessors, Perseverance can employ one of its computers just for navigation on the surface; its main computer can devote itself to the many other tasks that keep the rover healthy and active.
Editor’s note: the original article on the NASA website can be found here.
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